Effect of asperity size during contact between a thermal flying height control slider and a disk asperity

In order to increase recording density in hard disk drives (HDDs), thermal flying height control (TFC) sliders have recently been introduced to reduce the head-disk spacing to less than 2 nm [1]. Slider/disk contacts increase with a decrease in flying height, and consequently, the likelihood of disk failure due to slider/disk contacts increases [2]. Contacts occur predominantly between the thermal protrusion of TFC sliders and disk asperities, which in turn can cause wear and an increase of the temperature at the read and write elements [3-4]. Wear at the surface of the slider can cause loss of the read signal, while high interfacial temperatures can cause magnetic degradation of the read element. The goal of this study is to investigate the effect of asperity size on the plastic deformation and temperature rise of the read/write element due to contacts with disk asperities.